Tell about REST sort and data filter in guide.

[bscheshirwork]

We have new functional and can't guide chapter for it. However this functional have some specific options. For example, we can tell about undependent order of AR query set without "sort" param in API query. And tell about format of 'sort' - string with separator , and +/- instead array of params and ASC/DESC...
Add additional filter param without sort param in API query is change the order of AR query result set...